Department of Biochemistry, Center for Integrated Protein Science Munich, Ludwig-Maximilians-Universität München, Munich, Germany.
PLoS One. 2011;6(11):e27595. doi: 10.1371/journal.pone.0027595. Epub 2011 Nov 16.
Initiation of RNA polymerase (Pol) II transcription requires assembly of the pre-initiation complex (PIC) at the promoter. In the classical view, PIC assembly starts with binding of the TATA box-binding protein (TBP) to the TATA box. However, a TATA box occurs in only 15% of promoters in the yeast Saccharomyces cerevisiae, posing the question how most yeast promoters nucleate PIC assembly. Here we show that one third of all yeast promoters contain a novel conserved DNA element, the GA element (GAE), that generally does not co-occur with the TATA box. The distance of the GAE to the transcription start site (TSS) resembles the distance of the TATA box to the TSS. The TATA-less TMT1 core promoter contains a GAE, recruits TBP, and supports formation of a TBP-TFIIB-DNA-complex. Mutation of the promoter region surrounding the GAE abolishes transcription in vivo and in vitro. A 32-nucleotide promoter region containing the GAE can functionally substitute for the TATA box in a TATA-containing promoter. This identifies the GAE as a conserved promoter element in TATA-less promoters.
RNA 聚合酶（Pol）II 转录的起始需要在启动子处组装起始前复合物（PIC）。在经典观点中，PIC 组装始于 TATA 框结合蛋白（TBP）与 TATA 框的结合。然而，在酵母酿酒酵母中，只有 15%的启动子含有 TATA 框，这就提出了一个问题，即大多数酵母启动子如何引发 PIC 组装。在这里，我们表明，所有酵母启动子中有三分之一含有一个新的保守 DNA 元件，GA 元件（GAE），它通常与 TATA 框不共存。GAE 到转录起始位点（TSS）的距离与 TATA 框到 TSS 的距离相似。无 TATA 的 TMT1 核心启动子含有 GAE，招募 TBP，并支持 TBP-TFIIB-DNA 复合物的形成。GAE 周围启动子区域的突变会在体内和体外完全消除转录。含有 GAE 的 32 个核苷酸启动子区域可以在含有 TATA 的启动子中替代 TATA 框的功能。这表明 GAE 是无 TATA 启动子中保守的启动子元件。
